[unreadable] Positron Emission Tomography (PET) is a nuclear imaging technology that makes use of a range of positron-labeled tracers to provide images that reflect different parameters relevant to tumor biology. Recent developments in PET technology are leading towards more specialized PET systems, particularly for breast imaging and applications in breast cancer. Encouraging preliminary studies have been carried using whole-body PET scanners and while data from these studies has been most encouraging, it has also been recognized that currently available nuclear imaging instrumentation, such as whole-body PET systems, are not ideally suited for direct imaging of the breast. For this reason, there is a strong interest in developing dedicated gamma-ray imaging instrumentation optimized for breast imaging. In the proposed effort, we plan to investigate a novel approach to build a high resolution PET imager for breast cancer imaging which has ability to determine depth of interaction. High sensitivity, high resolution and compact design are additional advantages of the proposed design. [unreadable] [unreadable]